1. Field of the Invention
The present invention relates to a sticking material for preventing resticking, and, in particular, to a sticking material of packages for preventing resticking used, for example, as a price tag and a label stuck on the opening of a package.
2. Description of the Prior Art
Labels for preventing resticking used as price tage or the like, wherein suitable sewing stitches or cuts are provided on the base surface material, so that when any attempt is made, for example, in the shop to tear off the label and replace it with the other price tag, the label will separate and tear on the stitches or cuts, and such attempt can be distinguished by looking, have been known up to now.
A sticker placed on the opening of a package for indicating a sealed state can be easily removed for example, by picking up goods displayed on the shelves in the shop, depending on the material of the package opening and the surface treatment thereof, and restuck after placing foreign objects into the package, without it being noticed that the label was removed. Thus it is difficult to tell whether the package was opened just by externally examining the sticker. Therefore, there is a possibility that the contents of a package will be tampered with, for example, toxic substances will be added thereto.
Accordingly, recently, stickers sensitive to separation after adhesion have been introduced into the market.
The sticker comprises a film, and a silicon layer, having a vaporized metal layer on the surface which, is formed partly on the reverse side thereof. Thus, a part of the metallized layer is interposed by the silicon layer and is not metallized directly on the film. In addition, on the surface of the metallized layer, a pressure sensitive adhesive layer is formed, and a release sheet is adhered temporarily thereto.
The sticker is applied to the opening of the package by pressing the exposed surface of the adhesive layer after removing the release sheet. Then, when the sticker stuck on the opening is torn off, only the part of the metallized layer which was not metallized directly onto the film due to the silicon layer, remains as sticking on the opening, by the adhesive layer. Meanwhile, when the opening is unsealed, the metallized layer stuck and remained thereon will be cut or torn, and thereby the unsealed state can be distinguished.
However, such stickers have a disadvantage of their high cost, because the film is the material being metallized, and is limited to polyester or the like In addition, various other conditions must be satisfied, as the metal is vaporized on the surface and the silicon layer. Moreover, there were also such disadvantages and sanitary problems as the attachment of dusts on the sticky surface of the exposed adhesive layer, caused by part of the adhesive layer remained on the sticking portion of the material being stuck, when the film is torn off.